OBD-II Code P0514 — What It Means & How to Fix It

What Does This Error Mean?

P0514 means the battery temperature sensor is giving readings that fall outside the expected range or are not consistent with actual operating conditions. The battery temperature sensor helps the PCM regulate charging voltage — cold batteries need higher voltage to charge, hot batteries need less. When this sensor reads incorrectly, the PCM may over-charge or under-charge the battery. This code is most common in colder climates and on higher mileage vehicles where the sensor has degraded.

Affected Models

Most vehicles 2000 and newer with PCM-monitored battery temperature sensors
Common on GM vehicles (Chevrolet, GMC, Buick, Cadillac) — the sensor is typically on or near the battery
Ford vehicles with Battery Monitoring System (BMS)
Chrysler, Dodge, Jeep, and Ram vehicles with intelligent charging systems
Hybrid vehicles with high-voltage battery thermal management systems

Common Causes

Battery temperature sensor has failed — resistance drifted outside spec due to age
Sensor connector is corroded or loose, causing intermittent or incorrect readings
Sensor has been displaced from its mounting location — no longer in contact with the battery
Battery itself has been replaced without resetting the BMS, causing the PCM to use incorrect baseline data
Extremely hot or cold ambient temperatures pushing the sensor reading outside its normal operating range

How to Fix It

Locate the battery temperature sensor. On most vehicles it is clipped onto the battery housing, sitting under or beside the battery in the battery tray, or integrated into the battery cable assembly near the negative terminal.

On some vehicles the sensor is attached to a bracket in the battery box area — it may not be visible without removing the battery.
Inspect the sensor connector for corrosion and check that the sensor is physically attached to the battery. A sensor that has fallen off or been disconnected during battery service will give readings far outside normal range.

This is a surprisingly common cause — the sensor gets knocked loose when the battery is serviced and no one notices.
With the ignition on, use a scan tool to view the battery temperature sensor reading. Compare it to a thermometer reading near the battery. If the sensor reads significantly different from actual ambient temperature, the sensor has failed.

A 15°F or more difference between sensor reading and actual temperature usually indicates a failed sensor.
Measure resistance across the sensor terminals. Battery temperature sensors are NTC (negative temperature coefficient) thermistors — resistance decreases as temperature rises. Compare your reading at known temperature to the service manual specification table.

At room temperature (70°F/21°C), most battery temperature sensors read between 2,000 and 10,000 ohms depending on the manufacturer.
Replace the sensor if it reads out of spec. After replacement, reset the Battery Monitoring System if your vehicle has one. On many GM and Ford vehicles, the BMS reset requires a scan tool to write the reset command to the BCM or PCM.

Skipping the BMS reset after battery sensor work can cause the PCM to apply incorrect charging voltage, which shortens battery life.

When to Call a Professional

Battery temperature sensor replacement is usually a simple, inexpensive fix. However, on vehicles with Battery Monitoring Systems (BMS), the system must be reset after battery replacement — this often requires a dealer or shop scan tool. If the charging system is behaving erratically as a result, have the alternator output tested too.

Frequently Asked Questions

Will P0514 damage my battery?

Over time, yes — incorrect charging voltage shortens battery life. Overcharging causes battery fluid to evaporate and plates to corrode. Undercharging leaves the battery chronically low, which also accelerates sulfation. Fix P0514 to ensure the battery is getting the correct charge voltage.

Do I need to reset the BMS when I replace the battery?

Yes, on most modern vehicles. The Battery Monitoring System tracks battery health over time. If you install a new battery without resetting the BMS, the system continues using data from the old battery. This can cause overcharging or incorrect charging voltage. Ask your installer to reset the BMS, or do it yourself with a compatible scan tool.

How much does a battery temperature sensor cost?

The sensor itself is typically $10 to $40 at auto parts stores. If the sensor is integrated into the battery cable assembly, the cable assembly may need to be replaced — this costs more. Labor is usually minimal since the sensor is accessible without major disassembly.